[en] Hot water extract of sugar and red maple bark was addedto maple syrup and dried byfreeze (FD) and vacuum drum drying(VD) techniques. Addition of maple bark extracts to syrup helped to develop polyphenols-enriched maple sugar. X-ray diffraction revealed that sugar obtained from FD was amorphous in nature, while crystalline when dried by VD. Furthermore, the observation of maple sugar samples under scanning electron microscopy showed smooth and porous surface for FD sugar, while rough and grainy surface for VD sugar. Hausner ratio indicated that sugar produced by VD showed better flow characteristics than FD sugar. (Author)

[en] The present study has been undertaken with a view to prepare spinel ferrites of varying properties by applying the chemistry, evolved out of this investigation. Iron (III) oxalate was prepared, dried and exposed to different doses, 5.0-50.0x10^-2MGy of ⁶⁰Co γ-rays at room temperature. Simultaneous TG-DTA data were recorded by a Shimazdu, DTG-50 thermal analyzer under static air at a heating rate of 3 degC/min. The TG curves indicates two weight loss stages corresponding to (I) decomposition of Fe(III) to Fe(II) oxalate and (II) the latter to FeO, which undergoes disproportionation to give rise to Fe₃O₄

[en] Isothermal decomposition of γ-irradiated (1-4 MGy) strontium oxalate (anhydrous) has been carried out between 693-733K by gas evolution method. Data on both unirradiated and irradiated crystals are indicative of the fact that the process follows: (i) rapid initial gas evolution, (ii) acceleratory and (iii) decay stages. Irradiation enhances the rate of reaction without altering the mechanism of the process and the effect increases with increasing radiation dose. Analysing the data in the light of theories of different kinetic models, it is evident that two-dimensional phase boundary and Avrami-Erofeyev mechanism give best fit of the results. The energy of activation of the acceleratory period remains almost unaffected but that of the decay stage increases remarkably by irradiation, which may be ascribed to cage effect. (author)

[en] Influence of γ-irradiation, (10-500kGy) on the thermal decomposition of Y₂(C₂O₄)₃ + CuO (10 mol%) mixture has been studied in the temperature range, 603-643 K by gas evolution method. The (α- t plots indicate that decomposition of unirradiated and irradiated mixture follows (i) initial gas evolution, (ii) acceleratory period and (iii) decay stage. Irradiation promotes the initial gas evolution, α₁ and decreases the fractional decomposition, α_i at lower doses up to 50 KGy but the value increases at higher doses without affecting the nature of the isotherms. The data are analysed in the light of theories of various kinetic models and are found to be best fitted to Prout- Tompkins and Contracting Square mechanisms, suggesting that nucleation takes place instantaneously in a chain branching manner. The energy of activation of the acceleratory period is decreased but that of the decay stage is increased by irradiation. Plausible mechanism of decomposition and the effect of irradiation thereon has been discussed. (author)

[en] Mixed oxalates, viz., Ba-Ln (Ho, Gd, Tm and Y) oxalates were prepared by co-precipitation technique and characterized by chemical analysis and XRD method. The materials were exposed to different gamma doses (5.0-50.0 M rad) and their thermal decomposition were studied. The data were analyzed in the light of theory of different kinetic modes using Coats-Redfern equation. The Entropy of Activation Ϫs(+)of irradiated samples suggested the formation of low ordered activated complex compared to un irradiated materials and hadlower energy of activation as well as frequency factors. (author)

[en] Mixed oxalates, Ba-Ln (Ln=La, Pr, Gd, Ho, Tm and Y) were prepared by co-precipitation technique and characterized by chemical analysis and XRD study. The materials were exposed to different doses, 5.0-50.0 Mrad of ⁶⁰Co γ-rays and thermolysis study of both unirradiated and irradiated (25.0 Mrad) samples was carried out by DTG-50 thermal analyzer. The data are analysed in the light of theories of different kinetic models using Coat-Redfern Equation. It is indicated that irradiation decreases the onset and final temperature of decomposition and favours the process remarkably. In case of irradiated materials ΔS (+) values are obtained suggesting a faster reaction rate and less ordered activated complex formation comparing to unirradiated one. In most of the cases of the irradiated materials higher energy of activation as well as frequency factors, are obtained which may arise due to cage effect and generation of defects and dislocations in the crystal lattice. (author)

[en] The problem dealing with the two-phase flow of particulate suspension in a converging diverging channel has been analyzed. The basic equations governing the flow are reduced to a set of ordinary differential equations by using the appropriate transformations for the velocity components. The numerical solutions are carried out using numerical technique and the results are presented graphically. The flow phenomena have been analyzed for different physical parameters, Reynolds number, cross flow Reynolds number, angle of the channel, ratios of densities fluid and particle phases and momentum inverse stokes number. The effects of parameters on the velocity of the fluid and the skin friction has been discussed.